Editing Pikuach Nefesh (section)

==== Shabbos ====
Regarding the laws of Shabbos, there is special attention to the fact that they are set aside in cases of Pikuach Nefesh, as stated in the Gemara: "Desecrate one Shabbos for him so that he may observe many Shabbosos." The source of this principle is derived from the verse "The Children of Israel shall observe the Shabbos." An expression brought in the Gemara on this matter: "For a day-old living child, we desecrate Shabbos; for David, King of Israel, who has died, we do not desecrate Shabbos."

The Rebbe notes that the uniqueness of setting aside Shabbos for Pikuach Nefesh is also evident in the Rambam, who brings the law of setting aside Shabbos in the laws of Shabbos, and does not bring it in the place where he discusses other matters that are set aside for Pikuach Nefesh.

The Rebbe explains that there is an essential difference between setting aside Shabbos and setting aside other mitzvos - from a halachic perspective, for other mitzvos, Pikuach Nefesh '''pushes aside''' the mitzvah because it is greater and more important, whereas with Shabbos, it becomes '''permitted''' from the outset and becomes like a weekday. Therefore, there is a special source for setting aside Shabbos, teaching us that desecrating Shabbos to save a Jew is not a desecration at all, but rather, this desecration is part of observing Shabbos, since the purpose of Shabbos is to express "for it is a sign between Me and you," and when the Torah commands us to save Jewish life, it demonstrates the connection and Hashem's choice of the Jewish people.

The Alter Rebbe further clarifies in Tanya that the reason why Pikuach Nefesh does not override the mitzvos of idolatry, forbidden relations, and murder, while it does override other mitzvos of the Torah, is not because the other mitzvos are less stringent compared to these three mitzvos, but rather it is a divine decree. He proves this from Shabbos, which despite its stringency being equivalent to these three mitzvos, is nevertheless set aside in cases of Pikuach Nefesh.